feat(row6): a proposal whose approach declared no requirement is unsupported

Stress round 6 validated three falsification arms, and every validated
approach rested only on run-level declarations nobody can attribute to one
approach. declare_requirement now takes a required approach_id (a mandate
id or own-proposal; an unknown id is refused naming the valid ones), and a
ValidatedProposal whose approach has neither a mandate requirement nor a
declaration under its own id becomes validator.Unsupported - a Rejection
subclass carrying the validator's own ruling, reported as `unsupported` in
coverage, the outcome artefact, the settlement and the judge, and never
counted or summed. The rule is active whenever the debate held the
declaration tool, the micro base included; the road and pre-pass paths are
untouched. Declaration quality is not judged, so the rule can be satisfied
by declaring any document the run read.

The v1 gate's row 6 probes pass; its artefact half reads IKKE MÅLT because
stress round 6 predates approach-addressed declarations, and IKKE MÅLT is
never green - it fails the exit code.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_explore_callsites_loadbearing.py

@@ -634,7 +634,8 @@ async def test_a_hosted_exploration_shapes_the_mandate_the_run_evaluates(_hosted
         )
     )
 
-    assert body["outcome_type"] in {"validated", "rejected"}
+    # ``unsupported`` (row 6) is an evaluated outcome too: the numbers were judged.
+    assert body["outcome_type"] in {"validated", "rejected", "unsupported"}
     assert any(_LABEL in prompt for prompt in _hosted_backend), (
         "the shaped approach never reached a prompt — the hosted door does not wire the mandate"
     )